Facing new spruce budworm outbreak, Maine foresters look to history as a guide

By Ian DeBlieu, The Maine Monitor

From the summit of Katahdin, the view is of forests stretching in all directions, broken only by the western lakes, the alpine tundra of the Tablelands, and the rocky peaks of surrounding mountains: Woodlands as far as the eye can see.

Forty-five years ago this scene would have been quite different. A voracious insect called the spruce budworm was ravaging Maine’s North Woods, killing mountainsides of balsam fir and red spruce. Climbing Katahdin in September 1980, forestry habitat biologist Barry Burgason gazed southeast from the Knife Edge at a landscape of dead gray trees, “standing skeletons” on every slope.

“I’d had an idea of what it would look like from up there,” he said recently, “but I got the full perspective of how massive the outbreak was.”

As the insects moved south, Maine’s landowners rushed to harvest still-healthy trees. Thousands of acres of the North Woods were hastily clear-cut and sprayed with herbicides to knock back brush and hardwood trees that would crowd out commercially valuable species. Dense forests were replaced with stripped tracts of land.

Today, foresters and landowners are nervously tracking a renewed spruce budworm presence in the North Woods. The insects have already stripped hundreds of thousands of forested acres in Quebec and Ontario. 

Maine’s famed North Woods evoke images of expansive, healthy forests that are home to moose, bear and lynx. The reality is quite different.

After decades of heavy logging, scattered tracts are being managed with ecological timbering methods that strive to maintain natural systems — but most are not. Questions abound over how the state’s forests, both the northern timberlands and smaller, privately owned tracts throughout the state, will fare in a world beset by climate change.

Rapid ownership changes

More than 80 percent of Maine’s land is covered in forest. But what kind of woodlands are they? 

In 1986, Maine forest historian and economist Lloyd Irland described the northern portion of the state as “an immense junk woods” thanks to overharvesting, much of it spurred by the budworm invasion. Phyllis Austin, a respected Maine Times journalist, wrote that “the once high-quality forest is in the worst condition in history” from “the past mining of white pine, spruce, fir, and the most valuable hardwood species.”

Today, stands of late-stage and old-growth forest are few in number and are largely limited to reserves and difficult-to-cut sites on steep slopes or mountaintops. Scattered valuable trees remain, but foresters say they are being selectively cut in a damaging practice known as high grading.

Many of Maine’s woodlands hold a predominance of small trees with little commercial value, especially since the decline of the state’s paper and pulp industries. With the narrowing of age and species variety, the forests are less resilient to disruptions and disease.

The degradation of the timberlands has been exacerbated by widespread ownership changes. For a century, it was possible to gather the owners of the state’s timberlands in one small room. No longer. 

In the 1980s, after major changes to the U.S. tax code, short-term investors purchased significant tracts of timberland in Maine and elsewhere. They cut forests aggressively, gunning for annual investment returns of up to 6 percent, twice the average rate sought by Maine’s longtime timbering families. 

The rapid ownership changes spurred numerous regional and state efforts to regain control over what had long been a stable, mostly family-owned economic base. In public hearings, Mainers spoke of their fears that unbridled changes would weaken local economies and deprive residents of access to thousands of acres.

Articles by Phyllis Austin, Jym St. Pierre and others exposed industrial forestry practices that in 1996 and 1997 led to two ballot measures to ban or regulate clear-cutting. Following heated campaigns, both measures failed.

Regulatory efforts

After years of often bitter debate, in 1989 the Maine Legislature passed the Forest Practices Act, which enacted a partial ban on clear-cutting and established requirements for forested separation zones between clear-cuts. The legislation pleased almost no one.

“It has some teeth,” one forester said recently, “but it’s not based in science. It’s based in politics.”

The number of acres officially clear-cut each year fell during the 1990s. Yet conservationists said the rules did not go far enough and simply spurred landowners to increase the acreage cut each year.

“I don’t know that it’s possible to regulate good timber management,” said Robert Seymour, a forest researcher and University of Maine professor emeritus, explaining that there are too many complexities to cover in even several pieces of legislation.

Steve Tatko, vice president of land and conservation for the Appalachian Mountain Club, agreed: “Regulation alone will not produce sustainable management of forests.”  

A big factor needed to improve forest diversity and resilience, Tatko and others said, is economic incentives — especially a market for the small trees that crowd so many of Maine’s working forests. Once sought for paper and pulp production, they’re now so numerous that they’re an impediment to forest health.

Crowded groves

As Maine’s timberland owners grappled with forest management challenges after the spruce budworm epidemic, paper and pulp markets began to disintegrate. Demand for paper fell as communications moved online, and paper and pulp mills began to close. Furniture imports from China helped drive lumber mills out of business.

State employment figures show that in 1947 there were 18,400 paper mill jobs in Maine. By 2024, there were only 4,000.

Forests suffered the repercussions as well. Heavily cut tracts that were left untended have grown back as crowded, uniformly aged groves of mostly skinny trees, for which there is no longer a market. These stands might be rehabilitated, but the trees within many of them grow so close together that “I don’t know how you could get a machine into them to start thinning,” said Lloyd Irland.

The definition of “saw timber” — trees large enough to produce lumber — has decreased from above 11 inches in diameter to as little as five. “Big wood” was once 18 inches; now it’s nine.

Old growth

It’s not simply that younger woodlands contain a dearth of saw timber. Older forests are more diverse and complex, with snags, decaying logs, moist soils and mounded, uneven ground. These provide a patchwork of habitats for lichens, fungi, insects and small creatures at the base of the food chain. 

All that disappears with heavy cutting. As trees are removed, logging equipment scrapes and levels the forest floor. With little or no shade, the soils quickly dry. For a forest to develop the full characteristics of a healthy biological system, ecologist Janet McMahon noted, it needs to be left undisturbed for a century or more.

Patches of older forest still exist in Maine, but they are isolated. Borestone Mountain, an Audubon preserve, contains stands that date to the early 20th century. Big Reed Forest Reserve, a 5,000-acre sanctuary owned by The Nature Conservancy, has never been logged. Its remote location far from rivers helped save it. 

A study led by John Hagan, the former director of Manomet Conservation Science’s Maine program, analyzed aerial LiDAR images of the Unorganized Territory to identify stands of late-stage and old-growth forests, based on their rougher, more diverse canopy cover.

The study located numerous stands, but they tend to be on mountaintops or difficult-to-harvest steep slopes, with no connecting corridors for wildlife movement. Old-growth forests occupy slightly less than 1 percent of the Unorganized Territory, the study found, with another 3 percent in late-stage growth.

New threats

The Waldoboro town forest contains two-and-a-half acres of old trees, including numerous hemlocks as old as 260 years. Although protected from cutting, they are not necessarily safe. 

A sign at the trail entrance notes that hemlock woolly adelgids are present in the forest in large numbers. These small insects, which have decimated hemlock stands in mid-Atlantic states, are on the rise in Maine. Hikers can inadvertently carry eggs and larvae home on their shoes, spreading them to new forest stands.

Hemlock wooly adelgids are among a suite of invasive organisms from other continents that have placed Maine forest stands at risk. Aggressive plants include a barberry, a honeysuckle and a knotweed, all three from Japan. The emerald ash borer poses a grave threat to ash trees throughout Maine, including the brown ash trees prized by the Wabanaki Nations.

And there’s the coming spruce budworm invasion. Recent maps show budworm presence along the northwest boundary of Aroostook County and south of Fort Kent. “If an outbreak develops, the budworm could spread farther south depending on weather conditions, forest composition and budworm population dynamics,” Allison Kanoti, director of forest health and monitoring for the state, wrote in an email. 

Large, contiguous forest tracts with a heavy concentration of balsam fir and spruce are at the greatest risk, she wrote, adding, “An outbreak would not be of concern in southern Maine’s mixed and fragmented forests,” especially since fir and spruce are less prevalent there. “What to expect in Downeast Maine is a difficult question.”

The state’s Maine Spruce Budworm Task Force has outlined steps forest owners can take in at-risk areas to minimize damage, including insecticide spraying and removal of balsam fir trees, the budworms’ primary target. The task force will hold a spruce budworm informational session via Zoom from 1 to 4 p.m. on May 1.

Early intervention spraying measures that weren’t available in 1975 may help prevent a widespread outbreak, noted Seymour. The best defense, though, is to cultivate woodlands with a diversity of trees and reduce the concentration of fir and spruce, the budworms’ main target.

Foresters and northern Mainers remember all too well how the budworms moved across the landscape — whole mountainsides defoliated as if burned by a slow-moving fire. On a trip to Labrador six years ago, Barry Burguson saw new and extensive damage from budworms. It looked a lot, he said, like the defoliation in Maine forests during the 1970s and 1980s.

This story was originally published by The Maine Monitor, a nonprofit and nonpartisan news organization. To get regular coverage from the Monitor, sign up for a free Monitor newsletter here.